1. Field of the Invention
This invention relates to a portable identification transaction device such as a credit card, generally of thin relatively rigid plastic material, of a type which is carried by the public to enable it to make transactions, usually in a retail establishment, without the necessity of using cash.
2. Description of the Prior Art
Credit cards in current use ordinarily have printed thereon the name of the issuing financial establishment. In addition, the name of the user and his account number and the expiration date of the card are provided in raised type in order that the card may be placed in a device and the data imprinted. The card also commonly carries a magnetic strip which is readable by the device and identifies the user of the card.
Such credit cards are frequently stolen or unlawfully manufactured resulting in an unauthorized user being able to make purchases against the account of the card holder.
Another type of card in the prior art is that used in electronic funds transfer systems. These are inserted into a terminal machine located at the premises of a financial institution or other merchant. The user, by inserting his personal identification number (PIN) into the machine, can activate it and make deposits or withdraw cash from his account, or perform other transactions.
The Chaum U.S. Pat. No. 4,529,870, discloses a cryptographic device having a keyboard and which is useable with an external system in order to provide identification of the user and prevent unlawful use.
The Boutaleb et al. U.S. Pat. No. 4,536,014 discloses a credit card device having a liquid crystal mask covering an identity element. The mask can be changed to transparent form by inserting it between electrodes in a terminal machine.
The Weinberger U.S. Pat. No. 4,472,627, discloses a liquid crystal display in currency.
The Richard U.S. Pat. No. 3,624,938, and Jaffe U.S. Pat. No. 3,399,473, disclose credit cards having rotatable dials which, when set in predetermined positions, complete electric circuits.
The Benton U.S. Pat. No. 4,523,087, discloses a two-part portable verification device including a keyboard with a readout thereon, and a card which is insertable into the keyboard. The keyboard device is inserted into an external system which can optically read the readout from the keyboard device. The readout is not visible to the customer in order that he may not be aware of the data being transmitted between the keyboard device and the external device.
The Stuckert U.S. Pat. No. 4,277,837, discloses a personal portable terminal for financial transactions which is useable with external systems.